Derivative of Sine of Function

From ProofWiki
Jump to navigation Jump to search

Theorem

Let $u$ be a differentiable real function of $x$.

Then:

$\map {\dfrac \d {\d x} } {\sin u} = \cos u \dfrac {\d u} {\d x}$

where $\sin$ is the sine function and $\cos$ is the cosine function.


Proof

\(\ds \map {\frac \d {\d x} } {\sin u}\) \(=\) \(\ds \map {\frac \d {\d u} } {\sin u} \frac {\d u} {\d x}\) Chain Rule for Derivatives
\(\ds \) \(=\) \(\ds \cos u \frac {\d u} {\d x}\) Derivative of Sine Function

$\blacksquare$


Also see


Sources